A SURFACE COATING METHOD AND MEANS HEREFOR

Abstract: The invention relates to a method of coating a surface of a first material with a layer of a second material which cannot be cold-bonded to the first material and which possesses predetermined, desired surface properties, the material layer being produced under elevated temperature and pressure. The invention is characterized in at least partially melting the second material layer in direct contact with a third material that is capable of being cold-bonded, preferably a nonwoven type of material, so as to obtain a laminate which exhibits the predetermined, desired surface properties on one side thereof and good cold-bonding properties on the other side thereof; and affixing the laminate to the first material surface by gluing, cold-vulcanization or by some other suitable cold-bonding process. The invention also relates to means for use when coating a material surface with the intention of imparting predetermined, desired surface properties thereto.

Description: A SURFACE COATING METHOD AND MEANS HEREFOR The present invention relates to a method of coating a surface of a first material with a layer of a second material that cannot be cold-bonded to said surface and which has predetermined desired surface proper¬ ties, said material coating layer being produced under elevated temperature and pressure conditions. In our earlier Patent Application SE-A-9200022-2, we described a shock absorber which is intended to be mounted on a surface that shall be protected against impact forces. The outer elements of the shock absorb¬ er are manufactured of impact and wear-resistant rubber or plastic material. The shock absorber is suitable for use with the loading baskets of mine trucks, conveyors, material-handling equipment in sawmills, loading docks, ramps, etc. It is sometimes necessary to provide such shock-absorbing devices with an outer layer that has good sliding properties, for instance when used as a shock-absorbing support be¬ neath a conveyor belt in a loading zone, wherein the underside of the conveyor belt slides against a slide layer. The document mentions nothing in this respect as to how such slide layers can be mounted on the shock-absorbing device. However, it has been found in conjunction with the further development of shock-absorbing devices to which the present invention relates that serious problems are encountered with regard to mounting a desired slide or glide layer on the shock absorber. This problem resided in the impossibility of finding a surface layer of material of desired slide properties that could be applied to the device with the aid of known cold-bonding methods without the surface layer being loosened relatively quickly in the harsh envi¬ ronment in which such shock-absorbing devices are used. A closer analysis showed that this problem is more general when concerning coating material surfaces with other layers of material. Thus, there are several materials that cannot be cold-bonded in a way which will provide a sufficiently strong bond or joint. Particular mention can be made in this regard to coating elastic materials with other material layers with the intention of imparting to the elastic materi¬ al a surface which has given desired properties. The present invention surprisingly solves these prob¬ lems in an effective and efficient manner, and pro¬ vides a method of coating a surface so as to provide desired surface properties. The inventive coating method and the means herefor are characterized by the features set forth in the following Claims. As made evident in the introductory paragraph, when practicing the present invention the coating layer is comprised of a material which will enable the coating to be produced by pressure at an elevated temperature. In this regard, the coating layer is produced while at least partially melting the material in direct contact with a third material having the ability of being cold-bonded. This third material is preferably a nonwoven material, although it will also be understood that many conventional reinforcing materials used within plastic and rubber technology may also be used in the present context. This will result in a laminate which exhibits the predetermined, desired surface properties on one side thereof and good cold-bonding properties on its other side. The resultant laminate is then applied to the first material surface and bonded thereto with the aid of glue, by cold vulcani¬ zation or by some other convenient cold-bonding pro- cess. Conveniently, the second material is chosen from the group which includes rubber, plastic, Bakelite, metal alloy and like materials having desired surface prop¬ erties, for instance low surface friction. The invention is preferably intended for use when coating an elastic material, although it will be understood that other materials can be coated with other mate¬ rials in accordance with the invention. The inventive means is comprised of a laminate which is constructed of a material layer that possesses the desired surface properties, and a further material layer that possesses good cold-bonding properties, wherein the bonding surface between the layers has been formed by pressing the material layers together while at least partially melting the material that provides the laminate with said desired surface pro¬ perties. The invention will now be described in more detail with reference to convenient methods of carrying out the invention in practice. When practicing the inventive method, for instance to produce plastic sheets that are to be used to coat an elastic material or the like, nonwoven material is first placed in the bottom of a mould and the mould is then filled with an appropriate quantity of plastic granules and the granules then converted under elevat¬ ed temperature and elevated pressure to form a plastic sheet of a desired thickness. When the plastic sheet is removed from the mould, after being pressed and heated, it has the form of a laminate which comprises a plastic sheet on one side and nonwoven material on the other side. The nonwoven material is firmly bonded to the plastic sheet along a bonding surface which is determined by the at least partially molten plastic material and the extent to which this material has penetrated into the pores and interstices of the nonwoven material. Thus, an extremely intimate contact has been achieved between plastic sheet and nonwoven material and there is found in a laminate intermediate layer a "mixed structure" of plastic and nonwoven material that can only be achieved by means of such a method. The resultant, prepared laminate can then be readily glued or cold-vulcanized to rubber or to some other gluable material that is to be coated and given a specific surface property. It will be understood that the intention of the inven- tion is to provide a laminate which has good sliding properties, low friction or some other desired surface property on one side thereof and the other side of which can be fastened to another material having completely different physical properties with the aid of known cold-bonding methods.

Claims: CLAIMS 1. A method of coating a surface of a first material with a layer of a second material which cannot be cold-bonded to the first material and which has prede¬ termined desired surface properties, said material layer being produced under elevated temperature and pressure, characterized by producing the second layer by at least partially melting the second material layer in direct contact with a third material that is capable of being cold-bonded, preferably a nonwoven type of material, so as to obtain a laminate which exhibits the predetermined, desired surface properties on one side thereof and good cold-bonding properties on the other side thereof; and affixing the laminate to the first material surface by gluing, cold-vulcani¬ zation or by some other suitable cold-bonding process. 2. A method according to Claim 1, characterized by selecting the second material from the group compris¬ ing rubber, plastic, Bakelite and metal alloy. 3. A method according to Claim 1 and 2, characterized in that the first material is an elastic material. 4. A method according to Claim 3, characterized by choosing the second material from a group of materials having low surface friction. 5. Means for use when coating a material surface with the intention of imparting predetermined, desired surface properties thereto, characterized in that the means is comprised of a laminate which includes a material layer that possesses the desired surface properties and a further material layer that possesses good cold-bonding properties, wherein the bonding surface between the layers has been formed by pressing the material layers together while at least partially melting the material that is intended to provide the laminate with said desired surface properties.

Inventors: LINDQVIST HANS ERLING, LUNDSTROEM BO ANDERS, LINDQVIST, HANS, ERLING, LUNDSTROEM, BO, ANDERS
Applicants: LINDQVIST HANS ERLING, LUNDSTROEM BO ANDERS, VAERNAMO GUMMIFAB AB, AB VAERNAMO GUMMIFABRIK, LINDQVIST, HANS, ERLING, LUNDSTROEM, BO, ANDERS
Application year: 1994
Main classification: B32B25
IPC codes: B29C37, B32B7, B32B38, C08J5